Machine for folding paper box blanks on a stack thereof



Sept. 9, 1952 H. E. MONTGOMERY MACHINE FOR FOLDING PAPER BOX BLANKS ON ASTACK THEREOF 5 Sheets-Sheet l Filed June 3, 1948 H. E. MONTGOMERY Sept.9,4 1952 MACHINE FOR FOLDING PAPER BOX BLANKS ON A STACK THEREOF' FiledJune 5, 1948 3 Sheets-Sheet 2 Sept. 9, 1952 i H. E. MONTGMERYMACHINEfFOR FOLDING PAPER BOX BLANKS ON A STCK THEREOF 5 Sheets-Sheet 3Filed June 3, 1948 Patented Sept. 9, 1952 UNITED i-STATES PAT ENTOFICE tMACHINE FOR FOLDING PAPER BOX BLANKS ON A STACK THEREOF` Hugh E.Montgomery, Jacksonville,

ApplicationJune 3, 1948, Serial No. 30,847

`1 This inventionrelates to a machine for folding the topmost paper boxblank of a stack of blanks before removing the blank from the stack.Folding machines which have heretofore been made have withdrawn theblanks, one by one, from the top or bottom of a stack to a foldingstation where the end portions of the blank are folded over the centralportion,` the overlapping or abutting 'extremities of the foldedportionsV being thereafter joined by adhesive tape, metal staples, orothermeans. A i

According to the present invention, a machine is provided which holds astack of blanks and operates on the topmost blank while it is still inthe stack to fold'its end portions or aps over the mid-portion. Thefolded blank is then removed from the stack and transferred to astitcher or to a tape-applying mechanism. The mechanism hereinafterdescribed and claimed operates to apply suction cups to the flaps or endportions of the topmost blank of the stack and to Yrock these flapsupward, While the center portion is held down, so as to permit theintroduction of suitable folding arms under the raised flaps to completethe folding operation.

A more complete understanding of the invention may be had 'from thefollowing description thereof and from the drawings, of which- Figure 1is a front elevational view of a machine embodying the invention;

Figure 2 is a partial side elevation of the same;

Figure 3 is a fragmentary elevational view of a suction cup and thelinkage for actuating one of the folding arms;

Figure 4` is a similar view, showing the parts in different positions ofoperation;

Figure 5 is a partial plan view of the machine;

Figure 6 is a fragmentary sectional view, on the line B--B in'Figure 2,the partsjshown being in a different position of operation;

Figure 7 is a section on the line 1--1 of Figure 6;

Figure 8 is a section on the line 8-8 of Figure 6; and

Figure 9 is aperspective View of a typical blank to be folded. j

The machine is provided with a magazine holding a stack of blanks to befolded, and this magazine may be supported on a base 20 from which risea wall 2| and suitable uprights 22. These uprights support mechanism forelevating the stack of blanks gradually so that as the topmost blanksare folded and removed, one by one, the level of the top of the stack ismaintained substantially constant. Any suitable apparatus 6 Claims. (Cl.233-49) may be employed for elevating the stack during the operation ofthe machine. As shown, the blanks are stacked on agplatform 24 which isprovided with extensions 26 interiorly screwthreaded for threadedengagement with vertical screws 28. The latter are rotated slowly duringthe operation of the machine so as to elevate the platform 24 and thestack of blanks supported thereon, the rate of rotation being adjustedin accordance with the individual thickness of the blanks in the stack.

The folding operation is performedon the topmost blank while it is still`on the stack. This operationcomprises essentially two steps, namely, apreliminary vlifting of the end portions or flaps of the topmost blank,and, second, the completion of the folding operation by anotherinstrumentality. During the folding operation, the central portion ofthe blank is held down by ,suitable horizontal strips 3l) which aresupported by suitable members 32 from a longitudinal beam 34 at the topof the main frame.

A typical blank is shown in Figure 9, this blank having end portions orflaps 36 which are folded toward each other over the mid-portion of theblank until their end edges abut or overlap each other.

The initial lifting of the flaps of the topmost blank is done by liftingmechanisms, including suction cups 40 which are located over the endflaps of the blank, preferably near the extreme end thereof. The suctioncups 40 and their sup-i porting and operating apparatus are symmetricalin arrangement and movement so that a description of one supportingmeans will suffice for both. Referring to the lifting mechanism shown atthe left in Figure 1, the cup 4U is mounted at the lower end of avertical member 42 which is hollow and communicates at its upper endwith a flexible tube 44 leading to a suction pump (not shown). Themember 42 is integral with a horizontal hub member 46 in which is ashort shaft or pin 48. From the hub member 46 rises a vertical extension50 which is pivotally connected, as at 52, to a horizontal link 54, theother end of which is pivoted, as at 56, to a crank 58 mounted on ashaft B0. Rockable on the shaft 48 is a hub member 62 of a link 64 whichextends down to a bearing B6at the lower end of a vertical frame member68 secured to a transverse frame member 69.

` The bearing 66 is preferably located so that its rocking axis is nearthe line of bend of the flap of the blank which is to be folded. The hub62 is made hollow around the shaft 48 for a portion of its length so asto provide clearance for a spring which s coiled about the shaft 48 andengages the hub 62 and also the hub 46. The spring is tensioned in sucha manner as to impress on the hub 46 and the members 42 and 50 which areintegral therewith, a counterclockwise torque. A stop pin 12 is mountedon the vertical member 42 and is arranged to engage the link 64 tomaintain the member 42 in a vertical Vposition when the mechanism is inthe position shown in full lines in Figure 1.

When the crank 58 is revolved, the link 54 pulls the members 50 and 42toward the right, tending to rock these members about the shaft 46.Since such rocking movement is opposed bythe spring l0, the members 50and 42 and the link 64 rock as a unit about the axis of thebearing 66totheY position shown atA in dotted lines in Figure 1. Since the aXis ofthe bearing 66 is near the fold line of the ap, the cup 40 follows anarcuate path substantially identical with that of the portion of theflap which ittouches. When the cup frame reaches the position A, ,thehubs 46 and 62 `bring up against a stopv 74 whereupon further movementof the link 54 to the right rocks the members e2 and 50 about the axisof the shaft '43 so as to swing the suction cup 40 rapidly outward tothe positionv indicated in dotted lines at Bv in Figure 1, the cup 40then being clear' of the flap which is being folded. Immediately priorto the outward movement of the Ycup 40 from its normal position onl theupper surface of. the nap, suction is applied through the hose 44 so asto cause the flaptocling to the cup. When the cup is elevated to`position A, the flap is brought up with it. The underlying flap of. thenextfblank Yis prevented f -romcoming up with the top of the topmostblankby suitable retarding means, such as a brush 80 supported with itsbristles bearing against the endedges of the uppermost blanks.

When the cup,` 40' reaches. the position A, a horizontal arm 82 movesyinto the wedge-shaped space between the flap of the uppermost blank andthe underlying flap of the next blank so as to engage the'und'er surfaceof the uppermost flap, whereupon the suction is released so that thecupdil is free to move away from the flap to position B. The arm 82, asindicated in Figure e, continuesV its inward motion in an approximatelyhorizontal. path for about two-thirds of the distance between the endofthe flap and the line of fold. The arm thereupon moves through asubstantially semi-circular path pushing the lapahead ofit until theflap is folded to the position shown in Figure 4. The arm 82 thereuponmoves outward to the position indicated ata and is then ready for thenext folding operation. Y The suction cup i and the arm 82 at the righthand portion of the machine, as shownin Figure 1,

move through paths symmetrical with those ofV the left-hand cup and arm,hereinbefore described, and simultaneously therewith.

When the folding arms 8:2 are reachingA the position shownin- Figure e,completing the folding operation, alpusher 86 is actuated to pushtheblanktowardthe rear so that it passes between two successive pairs ofnarrow rolls twhichare deeplyA grooved circumferentially, the rolls ofeach pair being so spaced apart that thefolded edgesof. thefblankengage. in the grooves off-the rolls; VThis maintains the blank in itsfolded condition whileit is vpassing from Athe folding arms 82 either toconveyor belts ..90 byy which a` gummed tape 92 is appliedtojoin theends of the folded flaps, or-to a. stitching mechanism (notshown). Ifdesire'daninclined guide mem-V 4 ber 94 may be mounted adjacent to theupper conveyor belt 96, as indicated in Figure 1, to be engaged by theleading edges ofthe folded flaps as the blank approaches the conveyor.

The suction cups 40, the folding arms 82, and the pusher 85 are operatedin suitably timed relation by any suitable driving apparatus. As shownby way of example, a prime mover, such as an electric motor |00, ismounted on the main frame and is connected by a chain |02 to a sprocket|04 mounted on a shaft |06. The shaft |05 is connected by gear wheels|01 and |08 to a parallel shaft |09 which carries two worms ||0. Each ofthese worms is in mesh with a suitable worm gear on a short shaft ||2.On the same shaft with the worm gear is a gear wheel I I3 which mesheswith gear wheels ||4 and H6 of different sizes so that the gear wheel H4revolves once for each two revolutions of the gear wheel H6. Mounted torevolve with the gear wheel ||4 is a crank ||8, a crank |20 beingmounted to revolve' with the gear wheel ||6.

The folding arm. 82 is connectedto and supported by the respectivecranks ||8 and |20 by means of links |22 and |24. The result of thislinkage and the movements of Vthe cranks H8 and |20 is to impart to thefolding arm 82 a Figure 8 movement, such as is illustrated in Figure eof the drawings, the arm moving inward from the eXtreme positionindicatedgat a to a position beneath the uptilt'ed flap of the topmostblank, then in a somewhat semicircular path about the line of fold ofthe blank as an axis, then outwardly to the position a.

`In order to actuate the suction cups 4011i' suitably timed relationwith the movements of the folding arms 82, the shaft 60' is preferablydriven by suitable connections from the motor' |00. As shown, a verticalshaft |is connected by bevel gears |32 to the shaft |06 so as to bedriven thereby. At the upper end ofthe shaft V|30 is a worm ld whichmeshes with a gearv |35 mounted on a horizontal shaft |33. This shaft isconnected by bevel gears to a short vertical shaft |42 on which is alsomounted a gear wheel Ille. The latter meshes with a larger gearv wheelIE6 which is mounted on top of the main frame to rotate about a pivot|48. The' large gear wheel drives a smaller gear wheel whichis connectedby bevel gears |52 to the shaft 60.

For the actuationl of the pusher 8B', a connecting link |54 is pivotallyconnected, as at |56; to an eccentric point of the gear wheel |46, theother end or the link |54 carrying a; pin lstwhich `slides ina slot |62in the main frame'. Rotatably mounted on the pin is a pinio'nQl54 whichmeshes with Va xed rack |56 and also with a sliding rack |58. Thera-ck'|68 hasan extension |"|0,at the end of which is apin |12V carrying apinion |14 which meshes with av fixedI rack |15 and a sliding rack H82Thevp'u'sher is mounted on an arm which is secured tov the rack |76 andprojects downward therefrom, as shown in Figure 2. The pinions v|64 and|14, together with the fixed and movable racks with whiehthey aremeshed, are for the purpose of multiplying the strokes of the stud shaft|60 at the end of the link |54 so that the-pusher 86' will travelthrough a considerably greater distance in pushing thefolded blanks, oneby one', from the top of the stack.

The long screws 28 which elevate the platform 24 onwhich the stack ofblanks is carried are operatively connected to one or both ofthe-sliortshafts H2 by any `suitable means suchas-l bevel gears |84 and |86, thelatter being mounted on a shaft |88 which also carries a pulley |90. Abelt |92 connects the wheel |90 with a corresponding pulley |94 mountedon a shaft |96v on which is also mounted the gear wheel H4. Thus, withevery revolution of the gear wheel H4 the stack of blanks is elevated apredetermined amount substantially equal to the average thickness of ablank.

I claim:

1. A machine of the class described, comprising a magazine for holding astack of paper box blanks to be folded, hold-down means bearing on themid-portion of the topmost blank in the stack, and means for folding theend portions of. the topmost blank over upon the mid-portion thereof,said folding means including a suction cup arranged to engage the upperface of an end portion of the topmost blank at a point spaced from theline of fold of said end portion, means for causing said cup to travelupward in an arcuate path concentric with said line of fold andthereafter to swing out beyond the end edge of the blank, means forcompleting the folding of said end portion, and means for driving saidcup actuating means and said completing means in timed relation.

2. A machine of the class described, comprising a magazine for holding astack of paper box blanks to be folded, hold-down means bearing on themid-portion'of the topmost blank in the stack, means for initiallybending the end portions of said topmost blank up to inclined positions,said means including suction cups arranged to engage said end portionsand mechanisms for moving said cups through predetermined paths,automatic means for engaging under said inclined end portions andcompleting the folding of said end portions over on the mid-portion, andmeans for thereafter discharging the foldedblank from the stack.

3. A machine of the class described, comprising a magazine for holding astack of elongated paper box blanks, the end portions of which are to befolded over the mid-portions, hold-down means engaging the mid-portionof the topmost blank in the stack, a suction cup movable to engage eachend portion of the topmost blank, a supporting frame for each said cupoperable to lift the cup from a position upon the adjacent end portionof the top blank through an arcuate path approximately concentric vwiththe axis of fold of the said end portion of the blank to elevate saidend portion to an inclined position with reference to the plane of themid-portion, said frame being further operable to swing the cup outwardto clear the corresponding end of the blank so as not to interfere withthe completion of the folding of the end portions, means for actuatingsaid supporting frames to cause the cups carred thereby to describe saidarcuate paths and perform said outward swings in a predetermined timerelation.

4. In a machine for folding the end portions of a paper box blank overthe mid-portion thereof,

a suction cup arranged to engage the upper face of an end portion of ablank to be folded at a `point spaced toward the end of the` blank fromthe nearest line of fold, a vertical support member having said cupsecured to its lower end, a fixed pivot in substantial alignment withsaid line of fold, a lower link rockable at one end about said xed pivotand pivotally connected at its upper end to said vertical support memberat an intermediate point thereof, spring means at the joint of the linkand vertical member tending to rock the lower portion of said verticalmember toward said link, a stop to maintain a minimum angle between saidvertical member and link, an upper link pivotally attached to the upperend of said vertical member, means for periodically actuating said upperlink to rock said vertical member and lower link as a unit about saidfixed pivot, and a fixed stop engageable by said lower link to stop therocking thereof at a predetermined point, whereby further movement ofsaid upper link results in rocking said vertical member relatively tothe lower link, whereby the cup at the lower end ofthe vertical memberis swung out clear of the end of the box blank.

5. Apparatus of the class described, comprising means for supporting apaper box blank in a horizontal position, means for rocking an endportion of said blank upward about its line of fold through an acuteangle, and means for completing the fold of said end portion, the lastmentioned means including a horizontal rod extending transversely withrespect to the long axis of the blank, two supporting links eachpivotally secured at its upper end to the same end of said rod, twocranks rotatable about parallel axes and connected respectively to thelower ends of said links, and common means for driving said cranks intimed relation.

6. In a machine for folding paper box blanks, means for folding an endportion of a blank over upon its mid-portion, said means comprising apusher element adapted to engage under said end portion at a pointspaced from the line of fold and means for moving said pusher elementthrough a predetermined path, said moving means including two cranks ofdifferent length mounted to revolve about parallel axes, drivingconnections for rotating the shorter crank at twice the angular speed ofthe longer crank, and links operatively connecting each crank to saidpusher element.

HUGH E. MONTGOMERY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 669,027 Crosby Feb. 126, 19011,742,863 Jurgens Jan. 7, 1930 2,055,984 Pepper Sept. 29, 1936121,113,052 Kemp Apr. 5, 1938 2,336,507 Shields Dec. 14, 1943

